users = ["admin","Jack","Tom","Lucy","Jerry"]
for user in users:
    if user =="admin":
        print("Hello admin, would you like to see a status report?")
    elif users == None:
        print("We need to find some users!")
    else:
        print("Hello "+user+"thank you for logging in again.")
current_users = ["admin1","admin2","admin3","admin4","admin5"]
new_users = ["admin1","admin2","admin6","admin7","admin8"]
for new_user in new_users:
    if new_user.lower() in [current_user.lower() for current_user in current_users]:
        print(new_user+"已被占用，请输入别的用户名。")
    else:
        print(new_user+"可以使用。")
numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9]
for number in numbers:
    if number == 1:
        print("1st")
    elif number == 2:
        print("2nd")
    elif number == 3:
        print("3rd")
    else:
        print(str(number)+"th")